Drop-signal apparatus



(No Model.)

0. A. DANIELSON'. DROP SIGNAL APPARATUS.

No. 601,222. Patented M31222, 1898. F'yii I T 213 aigiwiw WITNESSES. y

wwfiw INVENTOI? @QMM A TTOHNE YS.

UNIT EI STATES PATENT "OFFICE.

OSCAR ALVIN DANIELSON, OF OWATONNA, MINNESOTA.

DROP-SIGNAL APPARATUS.

SPECIFICATION forming part of Letters Patent No. 601,222, dated March 22, 1898. Application filed May 13, 1897. Serial No. 636,350. (No model.)

T0 on whom it may concern:

Be it known that I, OSCAR ALVIN DANIEL- SON, of Owatonna, in the county of Steele and State of Minnesota, have invented a new and Improved Drop Signal Apparatus for Telephone Systems, of which the following is a full, clear, and exact description.

This inventionrelates to drop-signal apparatus used in connection with telephone-ekchange switchboards.

In operating manual switchboards it is necessary to leave a drop-magnet in the circuit between two telephones through which conversation is held. In order to accommodate a sufficient number of these magnets on a board, it is necessary to place them close together, and when so placed they are affected by induction-that is, a conversation-circuit passing through one magnet sets up induced currents in surrounding magnetsthusproducing what is termed cross-talk in the system. .'The object of my invention is toprovide a simple means to prevent the induction and consequently prevent cross-talk.

I will describe my invention,and then point out the novel features in the appended claims.

Reference is to be had to the accompanying drawings,forming a part of this specification,

in which similar characters of reference indicate correspondingparts in all the views.

Figure 1 is afdiagrammatic'view of a telephone system embodying my invention. Fig. 2 shows a switchboard with several drop-magnets arrangedthereon. Fig. 3 shows the mannor of winding one of the drop-magnets. Fig. 4 is a sectional view showing magnets as applied to an annunciator, and Fig. '5 is a rear view of a drop-releasing armature.

In carrying out my invention, instead of using a single magnet for each drop, I employ a series of magnets for each drop. As shown in the drawings, four electromagnets or two horseshoe-magnets are used for each drop, the positive magnets being indicated by 1 and the negative magnets by 2. The four magnets of a set are mounted on a soft-iron'base 3, and the several sets are arranged closely together on a switchboard. Each set of electromagnets is connected up in series, and the several sets are so arranged on the board that the The efi'ect upon adjacent sets of magnets may be described as follows, referring particularly I unlike, induce currents of opposite direction in w and y,which are wound alike. Therefore the currents induced in w and y meet and neutralize each other, likewise the cross effect of 00 upon y is balanced by 2 upon w. Of course it will be understood that these opposing effects are due to the different direction of winding of the magnets.

I have mentioned the magnets as being in series, but it is obvious that they may be con swing down to disclose the call on the plate 9.

Having thus described my invention, I claimas new and desire to secure by Letters Patent 1. In a drop-signal apparatus, a series of sets of magnets, a set for each drop, each set comprising a multiplicity of magnets, adjacent sets being so arranged that magnets of one set will oppose magnets of the adjacent set, substantially as specified.

2. In a drop-signal apparatus for telephone systems, a series of magnets for each drop, the magnets of a set being variously wound, and the said set being so arranged with relation to an adjacent set that magnets of the firstnamed set will oppose magnets of the adjacent set, substantially as specified.

3. In a drop-signal apparatus, a series of groups or sets of magnets, a group for each drop, each group comprising a multiplicity of magnets, the magnets of each group being oppositely wound, adjacent groups being so arranged that magnet-s of one group will oppose magnets of the adjacent group, substantially as specified.

4. In a drop-signal apparatus, a series of groups of magnets, a group being arranged for each drop, each group comprising a multiplieity of magnets and the magnets of each group being oppositely Wound, a soft-iron plate for each group of magnets, and a board upon which the several groups are arranged, the groups being so arranged on the board that the positive magnets of one set oppose negative and positive magnets of an adjacent set, substantially as specified.

OSCAR ALVIN DANIELSON. \Vitnesses:

J. W. ROWLAND, E. G. PORTER. 

